Unfortunately there aren't many ways to save money on gas at the pump. The only way (that I know of) to receive a discount on all your gas at literally every gas station in America is by using a no annual fee gas discount credit card.

There are several credit cards currently on the market which offer a discount on gas and no annual fee. Gas station credit cards, such as Shell and Exxon, usually only offer 3% off gas purchased from their station only. Although 3% is better than nothing, that is not a good reward program in my opinion since those name brand gas stations cost more anyway.

Your best bet is to go with a universally accepted rebate card which you can use at any gas station, such as the two offered at http://creditcardforum.com/rewards/51-special-gas-savings-offer.html

Credit Card Forum is offering two special cards. The Discover credit card will offer you a 5% rebate on your gas. You also have the option of doubling your rebate to receive 10%. On $4 gas that equals 20 cents and 40 cents per gallon you would be saving. This is a substantial savings considering that the discount is absolutely free. The card also offers the same rebate on car maintenance such as oil changes, tire replacements, etc. You can learn more about the Discover Open road credit card here: http://creditcardforum.com/rewards/44-review-discover-open-road-credit-card.html

American Express offers a card which has unlimited 5% cash back at gas stations. This card also offers the same 5% rebate on wireless (your cell phone bill), and office supplies, with a 1% rebate everywhere else. This is a very beneficial card for all around everyday spending since you will be earning big rewards for whatever you buy. The American Express card review at CreditCardForum can be found here: http://creditcardforum.com/american-express/37-review-american-express-simply-cash-business-card.html